Apparatus for applying liquid coating material to a continuous strand



NOV- 3 1964 A. MARzoccHl ETAL 3,155,543-

APPARATUS FOR APPLYING LIQUID COATING MATERIAL TO A CONTINUOUS STRANDFiled March l5. 1960 2 Sheets-Sheet 1 A 7 Tom/ins Nov. 3, 1964 3,155,543

A. MARZCCCHI ETAL APPARATUS FOR APPLYING LIQUID COATING MATERIAL TO ACONTINUOUS STRAND 2 Sheets-Sheet 2 Filed March l5. 1960 INVENTORSALF/PED M/mzoccf/f,

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United States Patent O 3,155,543 APlARATUS FR APPLYENS MQUHD CGA'ENGMATERIAL T A CONTINUQUS STRAND Aitred Marzocchi and Alhert E.lannarelli, Quinheriand,

and William ll. Miller, Chepachet, RJ., assigner-s to @wens-CorningFiberglas Corporation, a corporation of Delaware Filed Mar. l5, 1960,Ser. No. 15,191 7 Claims. (Cl. ils- 405) This invention relatesparticularly to apparatus for coating strands of fibrous glass, but alsomay be practiced advantageously for coating rovings, staple yarns,twine, cordage, and other types of strands ot various other natural orsynthetic bers as weil as monolament strands such as solid metallicwire, or encased metal strand conductors. The invention is also capableof utilization in contour-truing and finishing precoated or preformedelongated, cylindrical bodies.

nl order not to complicate the presentation of the invention, thedescription will be mainly directed to the use of the invention forcoating strands opiiorous glass with reference to the adaptability ofseveral, if not all of the features of the invention to the coating ofstrands of various other types.

Many procedures have been followed in coating strands of ibrous glass.Among these have been passing the strand over a pad saturated with thecoating material or in Contact with a roller or belt carrying thematerial,

having the strand travel through a dip tanlnspraying coating materialupon'a moving strand, and applying material to a strand and thendirecting the strand through a wiping die.

Of these methods, passing the strand over a saturated pad has provedvery satisfactory when the coating material has been of lightconsistency and it is desired to apply only a thin hlm. For acomparatively heavy overlay of material, the method utilizing a wipingdie has proved most successful.

There have, however, been serious difliculties encountered in thislatter method. First,y there has been a limit to how much material couldbe applied. This has required, in many instances, successive treatmentsto build up a coating of the desired thickness. It also has provedditcult to produce an even coating with this method.

Further trouble has been experienced with loose iibers' or fuzzcollecting in and clogging the die. This necessitates interruption ofproduction to remove the clogging' material. Another source of imperfectcoating in this technique has .been the settling of heavier componentsof the coating material.

The general object of this invention is to provide a more trouble-freemethod and apparatus for more uniformly coatingstrands.

A further object of the invention is the provision otl a method andapparatus which enables a heavier coating to be applied.

Another object is to create a coating of consistently high quality. Y

A still furthery object is tol apply novel coating compositions to bothmultiple and monolilament strands,

rThese and other ohjectsfand `advantages of the invenf and made moreround. It consequently moves more freely through the orice of the dieand is thus more able to receive a heavier deposit of the material.

Conversely, if the twist given the strand acts to loosen a twisttherein, the strand becomes more open and penetration by the coatingmaterial is improved.

These and other features and advantages or" the invention will behereafter described in more detail with reference made to theaccompanying drawings in which:

FIGURE 1 is a somewhat diagrammatic, side elevation of a yarn coatingproduction line incorporating coating devices embodying one form of thisinvention;

FGURE 2 is a fragmentary plan view of two of the coating devices of theproduction line shown in FIG- URE l;

IGURE 3 is an enlarged, side elevation and in part vertical section ofone of the coating devices of FIGURES l and 2;

lGURE 4 is an elevational view taken on the line ii-fl of FlGURE l or"the assembly of coating devices;

FGURE 5 is a schematic showing of an alternate arrangement of equipmentin the production line or" FlG- URE l;

. FlGURE 6 is a side elevation of coating apparatus embodying adifferent form of the invention;

FGURE 7 is a plan view of the apparatus of FlG- URE 6; and

FGURE 8 is a side elevation, with parts in vertical section, of coatingapparatus embodying another forni of the invention.

Referring to the drawings in more detail, the equipment included in theproduction line shown in FiGURE 1 starts with a yarn `feeding sta-tionin which six spools 3, on which strands of yarn 9 are wound, are mountedon a creel lll. The production line may, of course, be designed tohandle strandsv from a much larger number of spools than six.

, The strands 9, for example, will be considered as being single yarnswith a diameter of approximately .010 of an inch. Such a single end yarnusually includes either two or tour hundred glass filaments twistedtogether. The strands of yarn 9 may be drawnfrom the `spools 8 at mostany speed but which `usually ranges from one to five hund-red feet perminute. Strands from three ot' the spools, as here disclosed, are drawnthrough a guide eye l2 from which each of the three strands is :ledindividually through a guide loop l?. ln the same manner, the'strands 9from the lower three spool-sV S pass together through the guide eye i4and are then separated before going thr-ough the individual guide loopsl?.

The strands are thus initially aligned `for proceeding through thecoating apparatus ld. The strands are led across kin light contact withthe upper surface of the horizontal plate i9. Coat-ing material 2l isdelivered to the surface oplate 19 from goose-neck spouts 23. .Thismaterial is deposited upon the plates between the paths of the strandsand `spreads out .to be picked up there-by. The strands of yarn thenpass through the rotating dies 2S which distribute the coating materialaround the strands and control the amount of material left thereon.

The `coated strands l.'28 then proceed through the curing oven Si? wherethe coat-ing material is set by heat `and continue to the windupmechanism 32 where the strands are re-wound on wind-up spools 33.

The coating machine i6 is supported on a frame 34 within which is acoat-ing material supply tank 36. A pump 37 delivers material from thetank through a conduit 39 to a horizontal manifold d2, The material isforced therefrom through flow control valves ftd to the series oli'goosemeclt spouts 23. y 2 the material 2l flows over the plate 19 towardthe strands of yarn 9 into submerging contact therewith and PatentedNov. 3, 19t4 As shown in FlGURE is carried upon the strands over theedge of the plate 19 into the rotating dies 25. Excess material dropsdown between the plate and the dies to be received by the drain pipe 47and returned to the supply tank 36.

The dies 25 are usually rotated at a speed in the range of one to sixhundred revolutions per minute, but under some circumstances, the speedmay be increased to a considerably higher point. The die rotatingmechanism includes a series of spindles 50 journaled in bearings 51 andS2 in a series of vertically slidable channels 53. The spindles projectlaterally from slots 54 and 55, respectively located in side plates 56and 57 `of a casing 58. The dies 25 are frictionally held within thecylindrical sockets 59 on the rearward ends of the spindles 50.

Around each spindle is secured a rubber bushing 60. A V-belt 61, runningbetween pulleys 62 and 63, is normally in driving contact with thebushing 60. Pulley 62 is rotated by the electric motor and speed reducerassembly 65 through the belt 66. The assembly 65 is mounted on alaterally extending platform 67 as may be seen in FIGURES l and 4.

A row of idler pulleys 69 engage the upper course of V-belt 61 to pressthe belt against the spindle bushing 60. Springs '75 compressed `betweenthe channels 53 and the top of the casing 58 incline the spindles 50carried by the channels downwardly to hold the bushings 60 in engagingcontact with the V-belt 61.

The springs 75 are each positioned in encircling relation to a rod 76secured to the respective channel 53 and projecting upwardly from thecasing 58. A lever 77 pivoted to each rod 76 may be used to stop therotation of the associated die 25 by being turned to a verticalposition. This raises the respect-ive channel 53 through the connectingrod 76. The spindle 50 journaled in the channel is thus lifted away fromthe driving V-belt 61. Slots 54 and 55 in the side plates 56 and 57 ofthe casing 58 permit this upward movement of the spindle 50.

The coated strands of yarn 28 proceed from the hollow spindles 50 topass through the oven 30. The heating chamber 80 of 4the oven issupported upon legs 81. Heating elements 83 are designed to flnnishsuflicient heat to set the coating material whether by drying, curing,or otherwise hardening the material, depending upon its particularcomposition.

In the normal travel of the strands through the oven, the strands arenot in contact with the conveyor 85, as the latter is only utilized inlinitially feeding the strands through the oven. The conveyor 85 may bemounted for manual propelling around drums 86 and 87. Across theconveyor are slats 88 which are periodically notched crosswise of theslats. To start a strand through the oven its end is pressed into anotch of a slat in line with the path to be taken by the strand and theconveyor is operated to pull the strand to .the outlet of the oven wherethe strand may be grasped for leading through the subsequent windingmechanism 32.

Upon leaving the oven 30, the strands of yarn pass around the idlerrollers 90, 91, and 92 and travel down separately to the pairs of guiderollers 93.

Each strand then turns around a spring-biased tension pulley 94. Thevertical movement of the tension pulley, resulting from the pullthereon, controls the variable speed drive 95 operating the wind-upspools 33. Traversing mechanism 96 guides each strand back and forthupon its receiving spool 33.

In FIGURE is shown, schematically, additional equipment in the strandcoating line for incorporating dry, particulate material in the fluidcoating applied by the rotating die 25.

As there illustrated, the strand 97 with the coating in a sticky, unsetcondition has applied thereto a particulate material 9S which may beflakes or iibers of glass, other natural or synthetic fibers, or grainsor akes of various compositions. A supply of the selected particles ismaintained in a hopper 99 and kept in a loose agitated condition bysuitable paddles 101. The dry material adhered to the strand passingthrough the hopper 99 is smoothly embedded in the prime coating by thepassage of the strand through the forming die 103, which, as shown, isstationary but which could be mounted for rotation. In case anelectrical conductor wire is being made, or it is desired to apply aiinishing coat on some other product, a varnish or enamel is applied bythe spray nozzles 105.

An oven 107 may follow in the production line to finally set andconsolidate the coating layers of the resultant composite strand 108.

In FIGURES 6 and 7 is shown an alternate method of loading the strandswith coating material to replace the spouts 23 and plate 19 of theembodiment of FIGURES 1-3.

As there shown, the coating material is contained in a tank 112. A pump114 driven by motor 115 through belt 116 delivers the material from tank112 to a tube 117. There are slots 118 in the tube through which thestrands pass to pick up the coating material 119 which is delivered tothe tube from the pump by piping 121. Excess material is returned to thetank 112 through the return pipe 122. The valve 123 in this pipe is usedto regulate the amount of material which exudes from the slots 118. Thecoating material is returned to the pump through the piping 125 forrecirculation. A filter for removing foreign substances or largeparticles of the material could be located in this piping.

In the operation of the main embodiment disclosed, dies 25 with wipingapertures have a diameter of .015 of an inch may be selected forapplying a vinyl coating to heavy brous glass yarns for the fabricationof insect screening. Such screens have a higher burst strength than thatof any conventional screen cloth as well as outstanding durability. Theyarn diameter after coating with a colored vinyl is .0125 of an inch.The coating operation must be carefully executed in order to hide theunderlying white-appearing fibers, and the roundness of the coated yarnshould be as consistent as possible to minimize the eiect of the yarn inblocking the passage of light and air. The uniform roundness as well asa uniform thickness of the coating throughout the length and peripheryof the yarn also facilitates the Weaving or other process by which theyarn is assembled in reticulated form.

Such coated yarns are also utilized quite extensively for fabrics forupholstery, shoes, and handbags. For the best wearing performance, theseyarns should be thoroughly coated and impregnated. The vinyl ispreferably applied in a plastisol composition and as heavy a coating aspossible is frequently desired.

The vinyl material picked up by the strands of yarn passing over plate19 of the coating device of FIGURES 1-3 or in traversing the slots inthe tube of FIGURES 6 and 7, collects in the conical cavities of therotating dies 25. Here the vinyl plastisol is given a swirling actionwhich maintains the pigments in a dispersed state and acts to reduce theviscosity of the coating material. This reduction in viscosity wouldoccur with most thermoplastic materials and also with others iiuidizedby frictional working, and results in a more polished and thickercoating being deposited upon the strands as they pass out the restrictedoutlets of the dies. The coating material thus applied to the strand mayamount to as much or more than one and one-half times the fibrous glasscontent.

The vinyl coating material is delivered to each rotating die` 25continuously and at a rate which maintains the body of coating materialin the die at a constant volume. As it is dicult to feed the coatingmaterial at a rate precisely matching that of consumption, the rate ofdelivery is slightly above the rate of consumption and a small surplusof material drops down or is thrown off by the rotating die. Therotation of the die together with high linear movement of the yarncauses the material in the die to assume a symmetrical shape surroundingthe yarn.

The rotation of the dies alsoI has a very beneficial effect in regard toany loose bers or fuzz riding into the dies with the strands. Thesevagrant fibers are either wrapped mound the traveling strands to beimmersed in the coating material or slowly collect in a harmless ringwithin the die cavity. The customary clogging experienced withstationary dies is thus avoided.

With material with proper viscosity coupled with a die shaped to retainthe material at higher speeds of rotation, the material is given astronger whirling motion.

It is believed that the centrifugal thrust developed in the rotatingmaterial relieves the resistance to the traveling strand along the axisof the die and thus inclines to center the strand on the axis; and alsothat a rotatingr annular neck of the material surrounds the strand andlubricates its passage through the tapered outlet of the die.

With the rotational speed of the die high in respect to the forwardmovement of the strand and with a material of sufficient viscosity, atwist is momentarily effected upon the strand while within the die. Ifthis twist is in the direction of an existing twist in the yarn, theyarn will be momentarily tightened and made rounder. This eases itsmovement through the die outlet and allows more material to remainthereon. A twisting action tending to straighten an existing twist willopen the yarn for better penetration while reducing the amount ofmaterial left thereon. Any twist developed may be made permanent throughcorrelating twisting mechanism in the subsequent path of the strand.This would preferably be positioned beyond the oven.

Vanes on the interior of the die will, of course, serve to build up therotation of the coating material and its twisting influence on thestrand. The vanes or grooves on the interior of the die may be angled todevelop a forward propelling action upon the coating material and thuspositively force the material through the outlet of the die. For highspeeds the cavity in the die may be elongated and have an inwardlydirected annular flange to keep the material from being thrown out.Also, for better control and simplification the coating material may beprojected in a small stream directly into the die cavity.

An elongated and flanged die with material projected in a small streamthereto is illustra-ted in FIGURE 8. As there shown the goose-neck spout128 has an upturned outlet 129 adjacent the opening of the enlarged die13). A jet lil of coating material from the spout 128 maintains the body132 of coating material within the die at a constant volume with aslight excess escaping over the retaining flange E34 at the mouth of thedie.

There is hardly any limit to the Variety of coating substances which maybe applied to strands with the apparatus of this invention. Among thematerials more likely to be utilized are vinyls, polystyrenes, phenolformaldehydes, polyesters, polyethylenes, polyacrylates, polypropylenes,polyvinyl butyrals, cellulose derivatives, polyamides, oleo-resinousenamels, and (for solid wire strands) blends of polyvinyl formal andcresol formaldehyde resins.

Because of the stirring action provided by the rotating die, pigmentsare readily held in suspension in the coating material. Colored or metalcoated glass flakes when added as pigment to the basic coating substanceand applied to conductor wires not only provide attractive colors to theresulting coating, but also greatly improve the weatherability of theproduct. It has been found that the action of the die tends to orientparticulate components, with flakes positioned planarly.

The rotating die has proved very effective for coating texturized yarn.This type of yarn is fiufied up by jets of air or other means and hasnumerous lateral projections of fibers in loops or curl formations. The

loftiness and decorative nature of the yarn is not only maintained, butactually enhanced by the coating action of a rotating die. Prior coatingmethods have been inclined to normalize this special type of yarn bylaying the loops and smoothing out the contour. Also, with stationarywiping dies considerable clogging has been experienced due to the extraamount of fuzz characterizing this product.

Because of the lluidizing effect of the rotary die, coating materials ofgreater viscosity may be applied. This permits a reduction in thequantity of solvents or other fluid vehicles and a consequential savingin drying time and heat requirements.

The rotating die also effectively handles more highly plasticizedmaterials, which generally improve 4the final product besidescontributing exibility.

The polishing effect of the rotary die is due not only to the fluidizingof the coating material, but also toI the frictional contact between theoutlet of the die and the surface of the 'deposited coating material.The frictional action of the rotating die may be utilized alone indimensionally-truing and polishing strands previously coated and insmoothly contouring and finishing monfilament strands or rods of metal,other inorganic substances or organic materials. For this purpose, thedie outlet should be of suitable length and the speed of rotationselected to prevent spiral marking. v

T he concept of twisting a strand while in direct contact with a body ofcoating material is believed novel and a rotating die is considered thesimplest means for accomplishing this action. However, conventionaltwisting mechanism could be plaged adjacent to a stationary die coateror -to some other coating device for the same purpose.

It will be apparent that various changes and modifications, other thanthose discussed and disclosed herein, may be made in the apparatus andmethod of this invention without departing from the spirit of theinvention and the scope of the accompanying claims.

We claim:

l. Apparatus for applying a resinous liquid coating material to acontinuous strand including means for directing a strand along a linearpath, a die with an unobstructed,comparatively large entering mouth anda horizontal passage of substantial capacity tapered in section from themouth to an outlet of restricted size, said die being positioned in thepath of the strand whereby the strand travels axially through thehorizontal passage and the outlet of said die, means continuouslydelivering liquid resinous coating material through the mouth of the dieto the horizontal passage, said delivery of coating material being at arate to maintain a constant volume of the coating material within thehorizontal passage, and means rotating the die, the speed of rotation ofthe die and the speed of linear movement of the strand in combinationwith the capacity and shape of the die passage being such to cause thecoating material collected within the passage to whirl as a symmetricalbody around the strand passing therethrough.

2. Apparatus according to claim l in which the means continuouslydelivering resinous coating material includes a spout with an outletadjacent the mouth of the die.

3. Apparatus according to claim l in which the die has an inwardlydirected, material retaining flange around the mouth of the die.

4. Apparatus according to claim 1 in which there is a plurality of diesand common belt driving means for rotating the dies.

5. Apparatus according to claim 4, in which there is a mounting devicefor each die arranged to permit it to be separately disengaged from thecommon belt driving means.

6. Apparatus according to claim l in which the means for continuouslydelivering resinous coating material to the horizontal passage includesmeans for maintaining a continuous flow of coating material and forguiding the strand through the ow.

7. Apparatus for applying a liquid coating material to a continuousstrand including means for directing a strand along a linear path, a diewith a comparatively large entering mouth and an unobstructed horizontalpassage of substantial capacity extending from the mouth to an outlet ofrestricted size, said die being positioned in the path of the strandwhereby the strand travels axially through the horizontal passage andthe outlet of said die, means continuously delivering liquid coatingmaterial through the mouth of the die to the horizontal passage, saiddelivery of coating material being at a rate to maintain the horizontalpassage in a filled condition, and means rotating the die the speed ofrotation of the die and the speed of linear movement of the strand incombination with the capacity and shape of the die passage causing thecoating material to collect within and ll the passage and to whirlaround the strand passing therethrough.

References Cited in the tile of this patent UNITED STATES PATENTS1,735,850 Boedeker Nov. 19, 1929 1,938,627 Greenleaf Dec. 12, 19331,990,337 Lewis et al. Feb. 5, 1935 8 Bartell May 18, Lilley et al. Apr.2,6, Obermaier Sept. 27, Johnson Nov. 29, Hyatt et al. Feb. 6, DonovanIan. 14, Flynn July 8, Hill et al. Jan. 13, Flood Aug. 23, Keves Mar.21, Donnell et al. Apr. 24, Martin Sept. 4, Jones et al. Jan. 22, HeizerFeb. 3, Skive Aug. 4, Morrison Jan. 1, Bloem et al. Feb. 24, Smith Sept.22, Miller et al. Oct. 27, Bateson et al. Mar. 22, Abott Mar. 29,

FOREIGN PATENTS Great Britain Nov. 25,

1. APPARATUS FOR APPLYING A RESINOUS LIQUID COATING MATERIAL TO ACONTINUOUS STRAND INCLUDING MEANS FOR DIRECTING A STRAND ALONG A LINEARPATH, A DIE WITH AN UNOBSTRUCTED, COMPARATIVELY LARGE ENTERING MOUTH ANDA HORIZONTAL PASSAGE OF SUBSTANTIAL CAPACITY TAPERED IN SECTION FROM THEMOUTH TO AN OUTLET OF RESTRICTED SIZE, SAID DIE BEING POSITIONED IN THEPATH OF THE STRAND WHEREBY THE STRAND TRAVELS AXIALLY THROUGH THEHORIZONTAL PASSAGE AND THE OUTLET OF SAID DIE, MEANS CONTINUOUSLYDELIVERING LIQUID RESINOUS COATING MATERIAL THROUGH THE MOUTH OF THE DIETO THE HORIZONTAL PASSAGE, SAID DELIVERY OF COATING MATERIAL BEING AT ARATE TO MAINTAIN A CONSTANT VOLUME OF THE COATING MATERIAL WITHIN THEHORIZONTAL PASSAGE, AND MEANS ROTATING THE DIE, THE SPEED OF ROTATION OFTHE DIE AND THE SPEED OF LINEAR MOVEMENT OF THE STRAND IN COMBINATIONWITH THE CAPACITY AND SHAPE OF THE DIE PASSAGE BEING SUCH TO CAUSE THECOATING MATERIAL COLLECTED WITHIN THE PASSAGE TO WHIRL AS A SYMMETRICALBODY AROUND THE STRAND PASSING THERETHROUGH.